Equilibrium studies of the extraction of zirconium(IV) from sulfuric acid solutions with Di(2-ethylhexyl)phosphoric acid

Equilibrium studies were made at 25°C in the extraction of zirconium(IV) from sulfuric acid solutions with di(2-ethylhexyl)phosphoric acid (D2EHPA, HR) dissolved in kerosene. The reaction stoichiometry was numerically determined and the compositions of the extracted species were found to be ZrR₄ and ZrR₄(HR) at low loading ratios of D2EHPA (α < 0.09), but became ZrR₄ and ZrR₄(HR)₃ at relatively higher loading ratios (0.10 < α < 0.32). The equilibrium constants for the formation of these species were also obtained. Furthermore, numerical treatment of the experimental data excluded the existence of polynuclear complexes under the conditions studied (α < 0.32).     

二（2—乙基己基）硫代磷酸的合成

研究了新型萃取剂二(2-乙基己基)硫代磷酸的合成、纯化及结构鉴定。     

酯交换法合成邻苯二甲酸二异辛酯

以邻苯二甲酸二甲酯与异辛醇为原料,二丁基氧化锡为催化剂,通过酯交换法在无溶剂的条件下合成了邻苯二甲酸二异辛酯。通过实验考察了反应温度、催化剂用量、反应时间及物料配比等因素对反应的影响。反应的最佳条件是：反应温度为170～180℃,催化剂用量为1．0g,反应时间为4h,邻苯二甲酸二甲酯与异辛醇物质的量的比为1：2．10。在此条件下,收率在96．5％以上,通过折光率、IR、^1HNMR对产品进行了结构表征。     

加氢法生产环己烷1,2-二甲酸二(2-乙基己)酯工艺

以邻苯二甲酸二(2-乙基己)酯（DEHP,工业级）为原料,采用固定床加氢工艺和贵金属Ru-Pd催化剂,制备环己烷1,2-二甲酸二(2-乙基己)酯。分别考察了温度、压力、空速、氢气与原料的体积比对反应活性的影响。试验结果表明：在反应温度190℃、压力15MPa、体积空速0.5h?1、氢气与原料的体积比为800∶1的条件下,原料DEHP转化率保持在99.99%以上,目标产物选择性高于99.7%。连续运行1000h,催化剂仍具有优异的加氢活性。     

邻苯二甲酸二(2-乙基己基)酯对污泥好氧消化的影响

对邻苯二甲酸二(2-乙基己基)酯(DEHP)对污泥好氧消化的影响进行了研究,以期为污泥的安全资源化利用提供一定的基础资料。结果表明,对于污泥好氧消化,当进泥中DEHP投加量为20mg/L时,对VSS去除率没有明显影响;当DEHP投加量为100mg/L以上时,随DEHP投加量的增加,VSS去除率下降,同时反应器污泥中DEHP的残留浓度随之增大。     

SO_4~(2-)/TiO_2-Al_2O_3固体超强酸催化合成癸二酸二异辛酯

选择多种催化剂用于催化癸二酸和 2 乙基己醇合成癸二酸二异辛酯 ,研究了固体超强酸SO2 -4/TiO2 Al2 O3的催化性能 ,并考察了影响反应的因素 ,结果表明 ,适宜的反应条件为 :醇酸物质的量比为 3∶1;催化剂用量为 1.0g/mol癸二酸 ;带水剂甲苯为 10mL ;反应时间为 4 .5h ,酯化率达 98.5 %。     

Extraction of iron(III) from acidic sulfate solutions with bis(2‐ethylhexyl)phosphoric acid in PENRECO® 170 ES,a new friendly diluent

The extraction of iron(III) from acidic sulfate solutions by bis(2‐ethylhexyl)phosphoric acid (HDEHP) is investigated by using PENRECO® 170 ES as a diluent. PENRECO® 170 ES is new diluent which offers advantages such as improved solvency power, more complete phase disengagement and reduced losses in aqueous streams, with reductions of over 50% in diluent usage after 1 year, compared with conventional paraffinic diluents. The chemical analyses performed in the present work suggest that such properties arise, at least in part, from the presence of a series of hydrophobic branched alcohols in its composition (at least 0.6 mol dm^?3). In spite of the solvation effects due to these alcohols, HDEHP is dimeric in this diluent and, in the presence of an excess of HDEHP, the extraction of iron(III) takes place according to the classical equation: with K_ex = 10^{5.7 ± 0.2} (at I = 1 mol dm^?3). Such a value of K_ex is similar to that reported for pure hexane, which shows that the presence of long chain alcohols in PENRECO® 170 ES has no perceptible influence on the thermodynamics of iron(III) extraction by HDEHP. The extraction of iron(III) by HDEHP in PENRECO® 170 ES is slightly more rapid than in kerosene, which indicates that the molecules of alcohols constituting PENRECO® 170 ES have no negative effect on the kinetics of metal extraction although they compete with the extractant molecules for adsorption at the liquid–liquid interface. Stripping of iron(III) from loaded organic solutions by sulfuric acid is easy and rapid (95% equilibrium reached within 2 min) when HDEHP is used at moderate concentrations (typically 0.1 mol dm^?3). At higher HDEHP concentrations, stripping is difficult and incomplete, as found previously with other diluents. Thus, PENRECO® 170 ES is interesting in its ability to overcome some of the physical problems encountered in liquid–liquid operations, but its use does not modify significantly the chemistry of iron(III) extraction by HDEHP. © 2002 Society of Chemical Industry     

Thermodynamic studies of weak aqueous sulfate solutions in solvent extraction systems

The molalities and activity coefficients of various chemical species in the 0.5 M (H,Na,Me)SO₄ aqueous solutions (Me = Cu, Co or Zn) were calculated by the Bromley and the simplified Pitzer methods for strong electrolyte solutions. The validity of the conventional constant ionic medium method applied to these extraction systems was studied. The thermodynamic constants of these trace metal extractions with di(2-ethylhexyl)phosphoric acid (D2EHPA) were also evaluated, based on simple experiments and the calculated thermodynamic results.     

引发剂过氧化二碳酸二(2-乙基己)酯的红外光谱定性分析

运用傅立叶红外光谱技术 ,将常规的红外谱图解析程序和对比定性方法相结合 ,分析了PVC聚合用的引发剂过氧化二碳酸二 (2 -乙基己 )酯 ,并与其标准样品谱图及原材料氯代甲酸 2 -乙基己酯进行了对比定性分析 ,确定了各基团取代情况 ,为判定实验进展情况提供了可靠信息。     

酯交换法合成邻苯二甲酸二异辛酯

以邻苯二甲酸二甲酯与异辛醇为原料,有机锡为催化剂,通过酯交换法在无溶剂的条件下合成了邻苯二甲酸二异辛酯,考察了反应温度、催化剂用量、反应时间及物料配比等因素对反应的影响。结果表明,最佳反应条件为：反应温度170—180℃,催化剂用量1．0g,反应时间3．5h,邻苯二甲酸二甲酯与异辛醇物质的量比1：2．10。在此条件下,收率在96．5％以上,通过折光率、红外光谱分析、核磁氢谱对产品进行了结构表征。     

Extraction Behavior of Am(III) and Eu(III) from Nitric Acid Medium in Tetraoctyldiglycolamide-Bis(2-Ethylhexyl)Phosphoric Acid Solution

The extraction behavior of Am(III) and Eu(III) in a solution of tetra-octyldiglycolamide (TODGA), bis(2-ethylhexyl)phosphoric acid (HDEHP), and n-dodecane (n-DD) was studied to understand the role of TODGA and HDEHP in the combined solvent system. The extraction behavior of these metal ions was compared with those observed in TODGA/n-DD and HDEHP/n-DD. The effect of various parameters such as concentrations of HNO₃, TODGA, and HDEHP on the distribution ratio of Am(III) and Eu(III) was studied. Synergistic extraction of both the metal ions observed at lower acidities (<2.0 M) was attributed to the involvement of TODGA and HDEHP for extraction. However, the extraction of Am(III) and Eu(III) in the combined solvent was comparable with that observed in TODGA at higher acidities. The slope analysis of the extraction data confirmed the involvement of both the extractants at all acidities investigated in the present study.     

稀土固体超强酸SO_4~(2-)/TiO_2/La~(3+)催化合成邻苯二甲酸二(2-乙基)己酯

以稀土固体超强酸SO42-/TiO2/La3+为催化剂,邻苯二甲酸酐和2 乙基己醇为原料,合成邻苯二甲酸二(2 乙基)己酯,考察了影响反应的因素。结果表明,醇∶苯酐(质量比)=2.5∶1,催化剂用量为苯酐的5%,反应时间2 5h时,酯化率可达92.7%。     

Phenol Removal from Aqueous System by Bis(2-ethylhexyl) Sulfoxide Extraction

Solvent extraction is generally considered as one of the important and effective techniques to remove toxic phenol from wastewater. This paper explores the solvent extraction of phenol from wastewater using bis(2-ethylhexyl) sulfoxide (BESO) as extractant. Various parameters such as equilibrium time, the volume percentage of BESO, pH value, and ionic strength of the aqueous solution on the phenol extraction were investigated. The results indicated that BESO exhibited excellent performance of phenol extraction. The extraction percentage increased from 97.26% to 99.47%, varying the BESO concentration from 10% (v/v) to 30% (v/v). The extraction percentage decreased with increasing temperature in the range of 298-343 K. FTIR spectra of fresh and phenol loaded BESO organic phase indicated the existence of the hydrogen bonding interactions between S=O groups and phenol molecules. The relationship between log D and log [BESO] suggested the stoichiometry of the extracted species was a 1:1 complex, namely, [PhOH]·[BESO]. Phenol stripping from the loaded organic phase by sodium hydroxide was feasible, and more than 99% of phenol could be stripped when the NaOH concentration was 0.5 mol L^?1. The results obtained established that BESO/kerosene extraction system has potential for practical application in the phenol removal and recovery.     

Rate and mechanism of divalent metal transport through supported liquid membrane containing di(2-ethylhexyl) phosphoric acid as a mobile carrier

The rate and mechanism of copper, cobalt, nickel and zinc transport through a supported liquid membrane containing di(2-ethylhexyl) phosphoric acid as a mobile carrier were studied, respectively. The permeation rate equations have been derived taking into account aqueous film diffusion, interfacial chemical reaction and membrane diffusion as simultaneous controlling steps. The possible rate-controlling steps were estimated by comparing the relative values of the three successive resistances. The measured permeation rates of zinc agreed well with the proposed mechanism in this study.     

Extraction Equilibria of 4-Hydroxypyridine using Di (2-ethylhexyl) Phosphoric Acid

Extractions of 4-Hydroxpyridine (4HP) from aqueous solutions using Di(2-ethylhexyl)phosphoric acid (D2EHPA) as extractant in 1-octanol and kerosene were studied. The factors that affected the distribution coefficient (D), such as equilibrium pH, the concentration of D2EHPA, and the type of diluents were discussed. The interaction mechanism between 4HP and D2EHPA was validated by infrared spectroscopic analysis. D increased with the increase of the concentration of D2EHPA and peak values appeared at equilibrium pH = 3.6–5.0. D in the polar diluent (1-octanol) was much higher than those in the non-polar diluent (kerosene). The extraction reaction was found to be a proton-transfer process and D2EHPA mainly reacted through its –OH with –N– of 4HP. The apparent reactive extraction equilibrium constants K ₁₁ and K ₁₂ were obtained by fitting the experimental data of extraction equilibrium. By comparing calculated D values from the proposed model with the experimental ones, the accuracy of the proposed model was examined.     

无毒增塑剂柠檬酸三(2-乙基)己酯的合成

以柠檬酸和2-乙基己醇为原料,用氧化二正丁基锡为催化剂合成了无毒增塑剂柠檬酸三(2-乙基)己酯,考察了反应温度、催化剂用量、醇酸摩尔比、反应时间等因素对反应结果的影响,对合成的产品进行了红外光谱分析。实验结果表明,氧化二正丁基锡催化合成柠檬酸三(2-乙基)己酯的最佳反应条件为n(柠檬酸)∶n(2-乙基己醇)=1∶3.60,催化剂用量为柠檬酸质量的0.5%,反应时间为120min,反应温度为150～160℃,在最佳反应条件下,柠檬酸三(2-乙基)己酯收率在98%以上。     

Synergic Extraction of Folic Acid with Di(2-ethylhexyl) Phosphoric Acid and Amberlite LA-2

The influences of extractants concentrations and solvent polarity on the efficiency of folic acid separation by synergic extraction with Amberlite LA-2 and di(2-ethylhexyl) phosphoric acid (D2EHPA) mixture have been analyzed. The results indicated the formation of an interfacial compound which includes one molecule of folic acid and one of D2EHPA, the hydrophobicity of this compound being increased by solvation with Amberlite LA-2 molecules. The number of aminic molecules participating in the interfacial complex formation is controlled by solvent polarity and D2EHPA concentration, decreasing from 3 to 1 with the increase of these two parameters. The results indicated that the most important synergic effect corresponds to the extractants mixture dissolved n-heptane, at low D2EHPA concentration in the organic phase (5 g/l).     

Selective Extraction and Separation of Ce (IV) and Th (IV) from RE(III) in Sulfate Medium using Di(2-ethylhexyl)-N-heptylaminomethylphosphonate

The extraction and separation of Ce(IV) and Th(IV) from trivalent rare earths (RE, including scandium) in sulfate medium using di(2-ethylhexyl)-N-heptylaminomethylphosphonate (DEHAMP, L) were studied. The effects of H₂SO₄ concentration, extractant concentration, and temperature on the metal extraction were investigated systematically. It was found that the extraction of metal ions by DEHAMP decreases in the following order: Ce(IV) > Th(IV) > Sc(III) > other RE(III). A possible extraction mechanism was proposed and the extracted complexes as Ce(SO₄)₂·2L and Th(HSO₄)₂SO₄·L were determined by the slope analysis method. Thermodynamic parameters (ΔH, ΔG, and ΔS) were calculated. The extraction reactions of Ce(IV) and Th(IV) were each exothermic processes. The loaded Ce(IV) and Th(IV) can be stripped efficiently by 3% H₂O₂ and 4 mol/L HCl, respectively. The extraction capacity of 0.63 mol/L DEHAMP is 30.0 g/L CeO₂ and 24.4 g/L ThO₂, respectively. Furthermore, a solvent extraction process to selectively extract and recover cerium and thorium from bastnaesite leaching was proposed, by which the purities of cerium and thorium products reached 97.2% and 96.5% with a yield of 85.4% and 98.8%, respectively.